This P40 competitive renewal proposes to continue the aims of the initial grant application and expand the support of research investigators using baboons as models in biomedical and behavioral research. Not only have the investigators accomplished the aims of the initial grant proposal, but with the award of the R24 in July 2002 the investigators are now developing the SPF Baboon Resource. The OU Fort Reno Science Park Facility was completed in March of 2001 and became fully occupied by the summer of 2001. The facility provides four 0.5 acre outdoor corrals and eight large indoor gang cages for the group housing of baboons. The corrals are equipped with large climbing structures and concrete culverts. There is ample room for the large, multiple-male groups of baboons to exhibit species-typical behavior. Three adult males and from 25 to 30 adult female baboons with their infant and juvenile offspring populate each group. This social arrangement is typical for Papio (P.) anubis in the wild. The offspring remain in the corrals with their parents until they are needed for research. Many animals assigned to studies are later returned to their home corrals after the study period is completed. This scenario is characteristic of most vaccine protocols; baboons are removed in a group from a corral at Fort Reno, housed as a group at the Animal Resources Annex for the duration of the study, and then returned to as a group to the Fort Reno facility. The juveniles can remain together in the same corral until they reach puberty. The baboon colony has grown from 141 baboons at the outset of the P40 Grant support four years ago, to a colony of 284 baboons including 126 adult female baboons, 14 adult males, and 149 infants and juveniles. The investigators are presently housing 12 males, 115 adult females and their infant and juvenile offspring at the Fort Reno facility. During the last grant year, the investigators supplied 52 baboons to both OUHSC and outside research investigators. The investigators have published 18 articles and have supported National Institutes of Health (NIH) funded research programs at 12 outside intuitions during the last four years of the funding period. In order to accommodate increasing numbers of conventional baboons, the future plans include adding four new corrals to the present Fort Reno Facility. Additional plans include the construction of a separate, six-corral unit to house the SPF baboons. The investigators are adding two additional co-investigators who will expand the resource-based research. Uriel Blas-Machado, D.V.M., Ph.D., will characterize the parasitic protozoa Entamoeba (E.) histolytica that is endemic in the colony and in many colonies of baboons throughout the world. Dr. Blas-Machado will be assisted by the collaboration of Jonathan Ravdin, M.D., Chairman, Department of Medicine, University of Minnesota, College of Medicine. Dr. Ravdin is an expert in E. histolytica and has NIH funding to develop an oral vaccine for humans for protection from the organism. William A. Meier, D.V.M., Ph.D., Veterinary Pathologist at Oklahoma State University, will work with Dr. Ronald Kennedy and Dr. Christopher J. Miller, California National Primate Research Center, to develop reagents and methodologies to assess the cellular humoral and cellular immune response of baboons to infectious agents. The primary mission is to provide healthy and behaviorally normal baboons for biomedical and behavioral research to NIH-funded researchers at institutions across the United States. The investigators will offer the option of either selling baboons or leasing them for a use fee and ultimate return to the breeding colony.